@ -264,21 +264,23 @@ namespace storm {
* Here , 0 means a bad approximation and 1 means a good approximation .
*/
template < typename PomdpModelType , typename BeliefValueType >
typename ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : ValueType ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : rateObservation ( typename ExplorerType : : SuccessorObservationInformation const & info ) {
typename ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : ValueType ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : rateObservation ( typename ExplorerType : : SuccessorObservationInformation const & info , uint64_t const & observationResolution , uint64_t const & maxResolution ) {
auto n = storm : : utility : : convertNumber < ValueType > ( info . successorWithObsCount ) ;
auto one = storm : : utility : : one < ValueType > ( ) ;
// Create the actual rating for this observation at this choice from the given info
// Create the rating for this observation at this choice from the given info
ValueType obsChoiceRating = info . maxProbabilityToSuccessorWithObs / info . observationProbability ;
// At this point, obsRating is the largest triangulation weight (which ranges from 1/n to 1
// Normalize the rating so that it ranges from 0 to 1, where
// 0 means that the actual belief lies in the middle of the triangulating simplex (i.e. a "bad" approximation) and 1 means that the belief is precisely approximated.
obsChoiceRating = ( obsChoiceRating * n - one ) / ( n - one ) ;
// Scale the ratings with the resolutions, so that low resolutions get a lower rating (and are thus more likely to be refined)
obsChoiceRating * = storm : : utility : : convertNumber < ValueType > ( observationResolution ) / storm : : utility : : convertNumber < ValueType > ( maxResolution ) ;
return obsChoiceRating ;
}
template < typename PomdpModelType , typename BeliefValueType >
std : : vector < typename ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : ValueType > ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : getObservationRatings ( std : : shared_ptr < ExplorerType > const & overApproximation ) {
std : : vector < typename ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : ValueType > ApproximatePOMDPModelchecker < PomdpModelType , BeliefValueType > : : getObservationRatings ( std : : shared_ptr < ExplorerType > const & overApproximation , std : : vector < uint64_t > const & observationResolutionVector , uint64_t const & maxResolution ) {
uint64_t numMdpChoices = overApproximation - > getExploredMdp ( ) - > getNumberOfChoices ( ) ;
std : : vector < ValueType > resultingRatings ( pomdp . getNrObservations ( ) , storm : : utility : : one < ValueType > ( ) ) ;
@ -289,7 +291,7 @@ namespace storm {
overApproximation - > gatherSuccessorObservationInformationAtMdpChoice ( mdpChoice , gatheredSuccessorObservations ) ;
for ( auto const & obsInfo : gatheredSuccessorObservations ) {
auto const & obs = obsInfo . first ;
ValueType obsChoiceRating = rateObservation ( obsInfo . second ) ;
ValueType obsChoiceRating = rateObservation ( obsInfo . second , observationResolutionVector [ obs ] , maxResolution ) ;
// The rating of the observation will be the minimum over all choice-based observation ratings
resultingRatings [ obs ] = std : : min ( resultingRatings [ obs ] , obsChoiceRating ) ;
@ -303,6 +305,8 @@ namespace storm {
STORM_LOG_ASSERT ( ! refine | | refinementAggressiveness ! = nullptr , " Refinement enabled but no aggressiveness given " ) ;
STORM_LOG_ASSERT ( ! refine | | * refinementAggressiveness > = storm : : utility : : zero < ValueType > ( ) , " Can not refine with negative aggressiveness. " ) ;
STORM_LOG_ASSERT ( ! refine | | * refinementAggressiveness < = storm : : utility : : one < ValueType > ( ) , " Refinement with aggressiveness > 1 is invalid. " ) ;
uint64_t maxResolution = * std : : max_element ( observationResolutionVector . begin ( ) , observationResolutionVector . end ( ) ) ;
STORM_LOG_INFO ( " Refining with maximal resolution " < < maxResolution < < " . " ) ;
statistics . overApproximationBuildTime . start ( ) ;
storm : : storage : : BitVector refinedObservations ;
@ -315,7 +319,7 @@ namespace storm {
}
} else {
// If we refine the existing overApproximation, we need to find out which observation resolutions need refinement.
auto obsRatings = getObservationRatings ( overApproximation ) ;
auto obsRatings = getObservationRatings ( overApproximation , observationResolutionVector , maxResolution ) ;
ValueType minRating = * std : : min_element ( obsRatings . begin ( ) , obsRatings . end ( ) ) ;
// Potentially increase the aggressiveness so that at least one observation actually gets refinement.
* refinementAggressiveness = std : : max ( minRating , * refinementAggressiveness ) ;
@ -356,7 +360,7 @@ namespace storm {
overApproximation - > gatherSuccessorObservationInformationAtCurrentState ( action , gatheredSuccessorObservations ) ;
for ( auto const & obsInfo : gatheredSuccessorObservations ) {
if ( refinedObservations . get ( obsInfo . first ) ) {
ValueType obsRating = rateObservation ( obsInfo . second ) ;
ValueType obsRating = rateObservation ( obsInfo . second , observationResolutionVector [ obsInfo . first ] , maxResolution ) ;
stateActionRating = std : : min ( stateActionRating , obsRating ) ;
}
}